config: introduce set_or_die wrappers

A lot of call-sites for the existing family of `git_config_set`
functions do not check for errors that may occur, e.g. when the
configuration file is locked. In many cases we simply want to die
when such a situation arises.

Introduce wrappers that will cause the program to die in those
cases. These wrappers are temporary only to ease the transition
to let `git_config_set` die by default. They will be removed
later on when `git_config_set` itself has been replaced by
`git_config_set_gently`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -1523,11 +1523,15 @@ extern int git_config_maybe_bool(const char *, const char *);
 extern int git_config_string(const char **, const char *, const char *);
 extern int git_config_pathname(const char **, const char *, const char *);
 extern int git_config_set_in_file(const char *, const char *, const char *);
+extern void git_config_set_in_file_or_die(const char *, const char *, const char *);
 extern int git_config_set(const char *, const char *);
+extern void git_config_set_or_die(const char *, const char *);
 extern int git_config_parse_key(const char *, char **, int *);
 extern int git_config_key_is_valid(const char *key);
 extern int git_config_set_multivar(const char *, const char *, const char *, int);
+extern void git_config_set_multivar_or_die(const char *, const char *, const char *, int);
 extern int git_config_set_multivar_in_file(const char *, const char *, const char *, const char *, int);
+extern void git_config_set_multivar_in_file_or_die(const char *, const char *, const char *, const char *, int);
 extern int git_config_rename_section(const char *, const char *);
 extern int git_config_rename_section_in_file(const char *, const char *, const char *);
 extern const char *git_etc_gitconfig(void);

config.c

@@ -1831,11 +1831,22 @@ int git_config_set_in_file(const char *config_filename,
 	return git_config_set_multivar_in_file(config_filename, key, value, NULL, 0);
 }
 
+void git_config_set_in_file_or_die(const char *config_filename,
+			const char *key, const char *value)
+{
+	git_config_set_multivar_in_file_or_die(config_filename, key, value, NULL, 0);
+}
+
 int git_config_set(const char *key, const char *value)
 {
 	return git_config_set_multivar(key, value, NULL, 0);
 }
 
+void git_config_set_or_die(const char *key, const char *value)
+{
+	git_config_set_multivar_or_die(key, value, NULL, 0);
+}
+
 /*
  * Auxiliary function to sanity-check and split the key into the section
  * identifier and variable name.
@@ -2179,13 +2190,29 @@ int git_config_set_multivar_in_file(const char *config_filename,
 
 }
 
+void git_config_set_multivar_in_file_or_die(const char *config_filename,
+				const char *key, const char *value,
+				const char *value_regex, int multi_replace)
+{
+	if (git_config_set_multivar_in_file(config_filename, key, value,
+					    value_regex, multi_replace) < 0)
+		die(_("Could not set '%s' to '%s'"), key, value);
+}
+
 int git_config_set_multivar(const char *key, const char *value,
 			const char *value_regex, int multi_replace)
 {
 	return git_config_set_multivar_in_file(NULL, key, value, value_regex,
 					       multi_replace);
 }
 
+void git_config_set_multivar_or_die(const char *key, const char *value,
+			const char *value_regex, int multi_replace)
+{
+	git_config_set_multivar_in_file_or_die(NULL, key, value, value_regex,
+					       multi_replace);
+}
+
 static int section_name_match (const char *buf, const char *name)
 {
 	int i = 0, j = 0, dot = 0;